Appendix IL 903 at which opens a valve periodically, or the deposition of :r water contracts a plate or rod which opens the discharge i. Fig. 862 is a trap of the former type. The float D, 862. iced at E, is gradually lifted, and when it reaches a certain ht, the valve B opens, and pours the condensation water ugh G. F is a trial handle. The Steam Loop is an interesting contrivance by which the x from a separator is returned to the boiler. The usual supply A, Fig. 863, connects boiler B with cylinder c, and the steam tried by separator D. From the separator drain, the water is rned by riser E and drop-leg F, through the check valve G. N let the drain cock H be opened, so as to blow out the js E and F : when closing again, water will accumulate in the p-leg until there is sufficient weight to open the check valve G, le the steam behind it balances the boiler pressure. In this iner there will be an intermittent flow of water back to the >er, for the priming water will be carried up E as spray, and jn a sufficient weight has condensed in F, the check valve will >pen.